Compositions for reducing beta-amyloid-induced neurotoxicity comprising beta-secretase inhibitor

Abstract

Disclosed are a composition for reducing beta amyloid-induced neurotoxicity by inhibiting β-secretase activity, comprising a dibenzofuran derivative, and a method for preparing the same. Further disclosed is that the combination of the dibenzofuran derivative with a γ-secretase inhibitor or an anti-inflammatory agent shows higher activity with respect to reducing beta amyloid-induced neurotoxicity.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a composition for inhibiting β-secretase activity, comprising a dibenzofuran derivative as an active ingredient. Also, the present invention is concerned with a composition for reducing beta amyloid-induced neurotoxicity by inhibiting the production of β-secretase.[0003]2. Description of the Related Art[0004]Beta amyloid (Aβ), which is a peptide consisting of 40-42 amino acids, is formed after the sequential cleavage of the amyloid precursor protein (APP) by β-secretase (BACE, or Beta-site APP-cleaving enzyme) and γ-secretase.[0005]When secreted outside brain cells, the beta amyloid protein (Aβ) progressively forms highly neurotoxic plaques that injure brain cells, thus causing degenerative cognitive impairments such as Alzheimer's disease.[0006]In detail, β-secretase cleaves the amyloid precursor protein, a transmembrane protein of neurons, at the β-cleavage site to form the N-terminus ...

AI Technical Summary

Benefits of technology

[0014]It is therefore an object of the present invention to provide a composition which is of low cytotoxicity and is capable of inhibiting the production of β-secretase, thus effectively reducing beta-amyloid-induced neurotoxicity.

[0015]It is another object of the present invention to provide a composition for reducing beta-amyloid-induced neurotoxicity, which can be used in combination with pre-existing γ-secretase inhibitors so that the dosage and side effects of the pre-existing γ-secretase inhibitors can be minimized, with a concomitant maximal reduction in the beta amyloid level.

[0016]It is a further object of the present invention to provide a composition for reducing beta-amyloid-induced neurotoxicity, which can be used in combination with anti-inflammatory agents having a neurotoxicity reducing function so that the dosage and side effects can be minimized, with a concomitant maximal reduction in the beta amyloid levels.

[0021]In accordance with another aspect thereof, the present invention provides a composition for reducing beta amyloid-induced neurotoxicity, comprising a mixture of a dibenzofuran derivative selected from among the compound of Chemical Formula 3, the compound of Chemical Formula 4, and a mixture thereof and a γ-secretase inhibitor or an anti-inflammatory compound at a weight ratio of from 0.1:99.9 to 99.9:0.1.

[0023]Having effective inhibitory activity against β-secretase, the composition comprising the dibenzofuran derivative in accordance with the present invention can reduce the neurotoxicity induced by beta amyloid, one of the principal causes of neurodegenerative diseases, effectively and safely.

[0024]In addition, the composition for reducing neurotoxicity according to the present invention can be used in combination with γ-secretase inhibitor or an anti-inflammatory agent, which is difficult to apply to clinical practice due to its high toxicity and side effects as well as low clinical effects, so as to induce a synergistic effect far superior to the neurotoxicity reducing effects obtained by using them individually.

Problems solved by technology

When secreted outside brain cells, the beta amyloid protein (Aβ) progressively forms highly neurotoxic plaques that injure brain cells, thus causing degenerative cognitive impairments such as Alzheimer's disease.

Accordingly, antibodies against beta amyloid for neutralizing the toxicity of beta amyloid, and materials for inhibiting the production of amyloid precursor proteins have been researched and developed, but still not yet put into practice owing to insufficient clinical efficacy and major side effects.

As a result, γ-secretase inhibitors to were developed and have been under a lot of clinical investigation, but most of them are known to exhibit insufficient medicinal efficacy with major side effects.

Particularly, γ-secretase inhibitors also inhibit the Notch signaling pathway, causing the side effect of interrupting cell-cell communication.

However, peptide-based inhibitors lack practicality because their uptake into brain cells when administered orally is difficult.

Also, due to concerns about toxicity and side effects, synthetic compounds are anticipated to have little clinical effect in practice when administered over a long period of time.

However, since they exhibit significant side effects such as gastrointestinal hemorrhage, thrombosis, upon long-term administration or high dose administration, the use of them alone has not been enough to guarantee successful clinical achievements.

Almost all existing drugs that have been approved for use in the treatment of neurodegenerative diseases are highly toxic and at most temporally alleviate the symptoms.

None of them are known to exert substantial therapeutic effects on neurodegenerative diseases.

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